In such trucks the tines co-operate with apparatus such that the horizontal distance between the tines can be regulated to a suitable position under prevailing circumstances, and such that the tines can be moved laterally to an arbitrarily fixed distance therebetween.
Trucks provided with apparatus for regulating the horizontal distance between the tines are known to the art. Such trucks normally having two serially connected hydraulic cylinders with associated pistons, in which the piston rod of one piston acts on one tine and the piston rod of the other piston acts on the other tine.
It has been found that these hydraulic cylinders must normally be mounted on a homogeneous rectangular plate, having a height which corresponds approximately to the vertical part of the tine arrangement and a width which normally corresponds to the maximum width between the tines. The homogeneous rectangular plate is also provided with guides for the tines. The hydraulic cylinders and associated pistons are normally placed between guides, which means that the elements necessary for regulating the horizontal distance between the tines cover the major portion of the surface of the plate.
The use of the previously known apparatus has created a number of disadvantages, one of which being that the homogeneous plate is liable to obstruct the field of view of the driver when the horizontal leg of the tine arrangement is to be inserted beneath a pallet, a box or like object. This is particularly difficult when the tines are located at a height of 0.5-2.0 meters.
Thus, the homogeneous plate and the parts attached thereto create a difficult obstacle for the driver. In order to overcome the obscuring effect which the plate has on the driver, it is often necessary for the driver to lean far beyond the side of the truck, in order to be able to see well enough to position the tines correctly.
A disadvantage with two hydraulic cylinders, where one cylinder is intended for a respective tine, is that the cylinders must normally be coupled in series, which means that there is no guarantee that an initiated displacement of the tines will result in respective tines being displaced laterally to one and the same extent relative to a central vertical plane allotted to the truck for the purpose of deciding said lateral displacement. For example, it is not unusual for one tine to move more readily than the other and hence reach its terminal position of displacement before the other tine, which may be sluggish, has begun to move. Because of the homogeneous plate, it is practically impossible for the driver to determine the distance between the tines. When a load is lifted with only one tine in its terminal position of displacement the truck will be unevenly loaded which may result in serious problems.